1. Field of Invention
This invention relates to biosensors, and particularly to biosensors utilizing optical interference.
2. Description of Prior Art
Deoxyribonucleic acid (DNA) and protein identification are often required in biomedical and healthcare industry. They also play an important role in drug development and homeland security. Currently fluorescent detection is the most used DNA and protein testing method. The fluorescent detection, however, relies on fluorescent labels or tags and suffers from photobleaching, label or tag availability, and limited multiplexing capability. On the other hand, BioCD is a label-free scheme aimed for protein interrogation. But this method needs a compact disc (CD) system in operation. In consequence, the device is bulky in size and inconvenient to use. Device compactness and ease of operation are critical for the much desired on-chip biosensing solutions, such as the emerging lab-on-a-chip (LOC) or micro total analysis system (μTAS).
Therefore, there exists a need for a label-free or tag-free biosensing device which is compact in size and convenient to operate.